In recent years, PowerPoint and similar tools have revolutionized presentations, and it is easy to assume that the quality of slides and presentations has greatly improved. To the contrary, the general quality of both has suffered, perhaps in large part because of the ready availability of these tools. It is so quick and easy to enter lots of words and pictures into slides that the message is sometimes buried. Slides with too much detail overwhelm the listener and confuse the main point. It bears repeating: show only those slides that most effectively communicate your points.

However, the medium is not the message. Visual aids should help, not dominate, the presentation. Consider two extremes for slide presentations — a presentation with no slides and one with so many slides that the speaker could never realistically get through them all.

The best approach is to aim for just enough slides to support your message. Show only those slides that most effectively communicate your points and no more. Slides are visual aids that augment the talk — they are not the full report. Use them to communicate the main ideas of the presentation and to help you, the speaker, flow smoothly through the talk by prompting you for what needs to be communicated.

Text slides

Word slides should be used no more than necessary. Use them to help the audience follow where you are in the talk. They also are good for prompting, which helps you to stay relaxed and emphasize the key points.

Moreover, the content of a word slide should be sparse (i.e., just a few key words in bullet points, as in the conclusion slide shown in Figure 1). Wordy slides only encourage the audience into a reading exercise, diverting its attention away from where it should be addressed — listening to you.

Except when you are displaying data and concepts in graphics, your audience should be focused on you, listening to your words and registering the added emphasis conveyed through your facial and body language. Surprisingly, even in a large auditorium, audiences can see and benefit from gestures, which can be a useful visual aid for explaining ideas.

Talks can sometimes benefit from the use of an outline slide. An outline slide tells the audience what you are going to say, what you are saying, and then what you have said. By observing where your talk is heading, the audience will be better able to follow the presentation. Figure 2 illustrates an outline slide.

Too often, the first item in an outline slide is “Introduction” and the last one is “Conclusions.” These words are uninformative. Instead, the first point in the outline could be more explicitly stated, for example, “Motivation and Assumptions” or “Theory” or “Summary of Previous Studies.” The last item might be “Summary and Way Ahead,” for example. The outline should list what is unique to your presentation. Avoid including too many entries and making the font size too small.

It can be helpful to repeat the outline slide at appropriate places in the talk, highlighting the specific topic that you will cover next. This can help focus the audience on where you are taking them with your presentation. This is also a good place to pause in your story and allow the audience to digest your message. Explain what is coming next before springing the next slide on them.

Your bulleted slides should consist of key eye-catching words. A good start at simplifying them is to remove most, if not all, of the articles (“a,” “the”) and most of the verbs. We suggest never using the word “the” on a slide, and almost never the words “a” or “an.”

Keep it simple

A slide should not overwhelm the audience with detail. Slides are there to augment your talk so that the audience follows and remembers more of what you say. If you must illustrate all of the points contained in such a slide, then break it up, putting the content into several simple slides. Not only are simple messages in slides individually beneficial to the audience, but they help to simplify the entire story embodied by the presentation. This helps you to move smoothly through the storyline.

In particular, communicate just one key idea per slide. This helps your audience to follow your message. The use of sufficiently large lettering is especially helpful toward this end because it inherently minimizes the quantity of material that can be squeezed into a slide. The simpler the slides, the clearer, easier, and more straightforward is the talk. The clearer the talk, the greater the chance that a higher percentage of the audience will receive and understand the message. If the audience has to strain to see and interpret the message in your slides, it will be distracted from hearing the one coming from your lips.

We have seen presentations in which the speaker, while squinting to read his own slide, says “some of you might have trouble reading this slide.” For both graphics slides and word slides, give thought to aesthetics in the arrangement of the material, in particular margins and spacing of the content. Margins be should neither too small nor too large. Besides compromising the aesthetics, margins that are too large reduce the area available for the content.

Being a story, your presentation will naturally consist of parts that can be considered as chapters. Just as an extra blank page is often inserted prior to the start of each “chapter” in a book, it can aid your presentation if you add a slight pause prior to continuing on to the next chapter. When you display a slide, first describe what you are showing before discussing the interpretation. Since your talk is a story, it is more effective to say a few words about what is coming in that slide rather than bringing up the new slide before starting to talk about it. You want to ensure the audience understands the slide before you start making observations and drawing conclusions.

Final analysis

When your topic involves new technology, always clearly list the assumptions that you used in your research and the limitations imposed by those assumptions (i.e., over what range for the key parameters the technology is applicable). Also, let the audience know how the cost of applying this new technology compares with alternatives. In addition to providing all of the advantages of this great new methodology, also talk about the disadvantages, unresolved issues, and other sticking points to its application.

The scientific method that we all have been taught relies on testing various hypotheses. Some of these hypotheses are valid and generate reasonable results. Most will have limitations and cause the methodology to break under certain circumstances.

In your research, try to break your great new idea, and tell your audience about shortcomings that you have discovered. They will appreciate this and value your thoroughness and candor as well.

Presentations that effectively convey the results from a scientific project require a clear, concise, well-articulated talk supported by crisp, clear, easy-to-digest slides. Above all, empathize with your audience, and take care to help them grasp your message fully.

Not only will the audience benefit from your ability to convey complex ideas in simple terms, your reputation for conveying ideas will be enhanced. As a result, your peers will be inspired to seek you out to share their ideas with you. Good luck with your talks!

Editor’s note
A longer version of this article originally appeared in The Leading Edge. It has been reprinted with permission from that publication and the authors.